Artist Juan Ortiz is unveiling the August entries in his ongoing series of retro posters for original-series Star Trek episodes, and EW can exclusively share two of them with you. “Journey to Babel” featured the first appearance of Spock’s dad Sarek, who took the phrase “emotionally-distant father” to whole new levels. That episode was a deep-dive into Federation diplomacy, with the Enterprise hosting various ambassadors on a murder-filled space cruise. And then there’s “Plato’s Stepchildren,” an episode which featured one of the series’ more outré concepts (aliens modeling themselves after Ancient Greek culture) and the historic first-ever interracial kiss in scripted television, between Kirk and Uhura.